From Autism to Eating Disorders and More: The Role of Oxytocin in Neuropsychiatric Disorders

Potential mechanisms underlying the association between feeding and eating disorders and autism

There is a reliable association between autism and Feeding and Eating Disorders. Concerningly, where these two conditions co-occur, clinical outcomes of Feeding and Eating Disorders are significantly worse, and treatment less effective, than when the Feeding and Eating Disorders occur in neurotypical individuals. Problematically, the reason for the association between autism and Feeding and Eating Disorders is poorly understood, which constrains advances in clinical care. This paper outlines several possible mechanisms that may underlie the observed association and suggests ways in which they may be empirically tested. Mechanisms are split into those producing an artefactual association, and those reflecting a genuine link between conditions. Artefactual associations may be due to conceptual overlap in both diagnostic criteria and measurement, Feeding and Eating Disorders causing transient autistic traits, or the association being non-specific in nature. A genuine association between autism and Feeding and Eating Disorders may be due to common causal factors, autism directly or indirectly causing Feeding and Eating Disorders, and Feeding and Eating Disorders being a female manifestation of autism.

DNA methylation differences in genes associated with human personal disorders and deviant behavior

Epigenetic regulation of gene expression is involved in the progression of mental disorders, including deviant behavior, brain developmental, and personality disorders. The large number of genes has been studied for their activity association with stress and depression; however, the obtained results for the majority of these genes are contradictory. The aim of our study was to investigate the possible contribution of methylation level changes to the development of personality disorders and deviant behavior. A systematic study of CpG Islands in 21 target regions, including the promoter and intron regions of the 12 genes was performed in DNA samples extracted from peripheral blood cells, to obtain an overview of their methylation status. High-throughput sequencing of converted DNA samples was performed and calling of the methylation sites on the "original top strand" in CpG islands was carried out in the Bismark pipeline. The initial methylation profile of 77 patients and 48 controls samples revealed a significant difference in 7 CpG sites in 6 genes. The most significant hypermethylation was found for the target sites of the HTR2A (p-value = 1.2 × 10-13) and OXTR (p-value = 2.3 × 10-7) genes. These data support the previous reports that alterations in DNA methylation may play an important role in the dysregulation of gene expression associated with personality disorders and deviant behavior, and confirm their potential use as biomarkers to improve thediagnosis, prognosis, and assessment of response to treatment.

Control of lipolysis by a population of oxytocinergic sympathetic neurons

Oxytocin (OXT), a nine-amino-acid peptide produced in the hypothalamus and released by the posterior pituitary, has well-known actions in parturition, lactation and social behaviour1, and has become an intriguing therapeutic target for conditions such as autism and schizophrenia2. Exogenous OXT has also been shown to have effects on body weight, lipid levels and glucose homeostasis1,3, suggesting that it may also have therapeutic potential for metabolic disease1,4. It is unclear, however, whether endogenous OXT participates in metabolic homeostasis. Here we show that OXT is a critical regulator of adipose tissue lipolysis in both mice and humans. In addition, OXT serves to facilitate the ability of β-adrenergic agonists to fully promote lipolysis. Most surprisingly, the relevant source of OXT in these metabolic actions is a previously unidentified subpopulation of tyrosine hydroxylase-positive sympathetic neurons. Our data reveal that OXT from the peripheral nervous system is an endogenous regulator of adipose and systemic metabolism.

Oxytocin Receptor Expression in Hair Follicle Stem Cells: A Promising Model for Biological and Therapeutic Discovery in Neuropsychiatric Disorders

The intricate nature of the human brain and the limitations of existing model systems to study molecular and cellular causes of neuropsychiatric disorders represent a major challenge for basic research. The promising progress in patient-derived stem cell technology and in our knowledge on the role of the brain oxytocin (OXT) system in health and disease offer new possibilities in that direction. In this study, the rat hair follicle stem cells (HFSCs) were isolated and expanded in vitro. The expression of oxytocin receptors (OXTR) was evaluated in these cells. The cellular viability was assessed 12 h post stimulation with OXT. The activation of OXTR-coupled intracellular signaling cascades, following OXT treatment was determined. Also, the influence of OXT on neurite outgrowth and cytoskeletal rearrangement were defined. The assessment of OXTR protein expression revealed this receptor is expressed abundantly in HFSCs. As evidenced by the cell viability assay, no adverse or cytotoxic effects were detected following 12 h treatment with different concentrations of OXT. Moreover, OXTR stimulation by OXT resulted in ERK1/2, CREB, and eEF2 activation, neurite length alterations, and cytoskeletal rearrangements that reveal the functionality of this receptor in HFSCs. Here, we introduced the rat HFSCs as an easy-to-obtain stem cell model that express functional OXTR. This cell-based model can contribute to our understanding of the progression and treatment of neuropsychiatric disorders with oxytocinergic system deficiency.

Impact of virtual adjunctive cognitive remediation therapy on cognitive flexibility and treatment outcomes in comorbid anorexia nervosa and exercise dependence as quantified using novel biomarkers: A stage 1 registered report

OBJECTIVE

Anorexia nervosa (AN) is associated with significant individual mental and physical suffering and public health burden and fewer than half of patients recover fully with current treatments. Comorbid exercise dependence (ExD) is common in AN and associated with significantly worse symptom severity and treatment outcomes. Research points to cognitive inflexibility as a prominent executive function inefficiency and transdiagnostic etiologic and maintaining mechanism linking AN and ExD. This study will evaluate the initial efficacy of adjunctive Cognitive Remediation Therapy (CRT), which has been shown to produce cognitive improvements in adults with AN, in targeting cognitive inflexibility in individuals with comorbid AN and ExD. As an exploratory aim, this study also addresses the current lack of quick and cost-effective assessments of cognitive flexibility by establishing the utility of two proposed biomarkers, heart rate variability and salivary oxytocin.

METHOD

We will conduct a single-group, within-subjects trial of an established CRT protocol delivered remotely as an adjunct to inpatient or intensive outpatient treatment as usual (TAU) to adult patients (n = 42) with comorbid AN and ExD. Assessments, including self-report, neuropsychological, and biomarker measurements, will occur at three time points.

RESULTS

We expect CRT to increase cognitive flexibility transdiagnostically and consequently, along with TAU, positively impact AN and ExD compulsivity and symptom severity, including weight gain.

DISCUSSION

Findings will inform the development of more effective integrative interventions for AN and ExD targeting shared mechanisms and facilitate the routine assessment of cognitive flexibility as a transdiagnostic risk and maintaining factor across psychopathologies in clinical and research settings.

PUBLIC SIGNIFICANCE

Patients with anorexia nervosa often engage in excessive exercise, leading to harmful outcomes, including increased suicidal behavior. This study examines the preliminary efficacy of an intervention that fosters flexible and holistic thinking in patients with problematic eating and exercise to, along with routine treatment, decrease harmful exercise symptoms. This study also examines new biological markers of the inflexible thinking style thought to be characteristic of anorexia nervosa and exercise dependence.

Oxytocin protective effects on zebrafish larvae models of autism-like spectrum disorder

Objectives

Autism is a complicated neurodevelopmental disorder characterized by social interaction deficiencies, hyperactivity, anxiety, communication disorders, and a limited range of interests. The zebrafish (Danio rerio) is a social vertebrate used as a biomedical research model to understand social behavior mechanisms.

Materials and Methods

After spawning, the eggs were exposed to sodium valproate for 48 hr, after which the eggs were divided into eight groups. Except for the positive and control groups, there were six treatment groups based on oxytocin concentration (25, 50, and 100 μM) and time point (24 and 48 hr). Treatment was performed on days 6 and 7, examined by labeling oxytocin with fluorescein-5-isothiocyanate (FITC) and imaging with confocal microscopy and the expression levels of potential genes associated with the qPCR technique. Behavioral studies, including light-dark background preference test, shoaling behavior, mirror test, and social preference, were performed on 10, 11, 12, and 13 days post fertilization (dpf), respectively.

Results

The results showed that the most significant effect of oxytocin was at the concentration of 50 μM and the time point of 48 hr. Increased expression of shank3a, shank3b, and oxytocin receptor genes was also significant at this oxytocin concentration. Light-dark background preference results showed that oxytocin in the concentration of 50 µM significantly increased the number of crosses between dark and light areas compared with valproic acid (positive group). Also, oxytocin showed an increase in the frequency and time of contact between the two larvae. We showed a decrease in the distance in the larval group and an increase in time spent at a distance of one centimeter from the mirror.

Conclusion

Our findings showed that the increased gene expression of shank3a, shank3b, and oxytocin receptors improved autistic behavior. Based on this study some indications showed that oxytocin administration in the larval stage could significantly improve the autism-like spectrum.

Modulation of the thermosensory system by oxytocin

Oxytocin (OT) is a neurohormone involved early in neurodevelopment and is implicated in multiple functions, including sensory modulation. Evidence of such modulation has been observed for different sensory modalities in both healthy and pathological conditions. This review summarizes the pleiotropic modulation that OT can exercise on an often overlooked sensory system: thermosensation. This system allows us to sense temperature variations and compensate for the variation to maintain a stable core body temperature. Oxytocin modulates autonomic and behavioral mechanisms underlying thermoregulation at both central and peripheral levels. Hyposensitivity or hypersensitivity for different sensory modalities, including thermosensitivity, is a common feature in autism spectrum disorder (ASD), recapitulated in several ASD mouse models. These sensory dysregulations occur early in post-natal development and are correlated with dysregulation of the oxytocinergic system. In this study, we discussed the potential link between thermosensory atypia and the dysregulation of the oxytocinergic system in ASD.

Do the diverse phenotypes of Prader-Willi syndrome reflect extremes of covariation in typical populations?

The phenotypes of human imprinted neurogenetic disorders can be hypothesized as extreme alterations of typical human phenotypes. The imprinted neurogenetic disorder Prader-Willi syndrome (PWS) features covarying phenotypes that centrally involve altered social behaviors, attachment, mood, circadian rhythms, and eating habits, that can be traced to altered functioning of the hypothalamus. Here, we conducted analyses to investigate the extent to which the behavioral variation shown in typical human populations for a set of PWAS-associated traits including autism spectrum cognition, schizotypal cognition, mood, eating, and sleeping phenotypes shows covariability that recapitulates the covariation observed in individuals with PWS. To this end, we collected data from 296 typical individuals for this set of phenotypes, and showed, using principal components analysis, evidence of a major axis reflecting key covarying PWS traits. We also reviewed the literature regarding neurogenetic syndromes that overlap in their affected traits with PWS, to determine their prevalence and properties. These findings demonstrate that a notable suite of syndromes shows phenotypic overlap with PWS, implicating a large set of imprinted and non-imprinted genes, some of which interact, in the phenotypes of this disorder. Considered together, these findings link variation in and among neurogenetic disorders with variation in typical populations, especially with regard to pleiotropic effects mediated by the hypothalamus. This work also implicates effects of imprinted gene variation on cognition and behavior in typical human populations.

Individual Characteristics and Pain Sensitivity during Pregnancy-A Cross-Sectional Study in Pregnant and Non-Pregnant Women

The aim of the study was to describe the characteristics and factors related to pain perception in pregnant women, such as optimism, personality traits, and fear of developing COVID-19 consequences. Sixty-six pregnant women aged 23 to 42 years participated in the study, and the comparison group consisted of n = 59 non-pregnant female students aged 19 to 23 years. Pressure pain threshold and pain tolerance were measured with an algometer. To assess psychological characteristics, the Life-Orientation Test-Revised was used to assess optimism, the Fear of COVID-19 Scale was used to assess COVID-19 anxiety, and the Ten-Item Personality Inventory was applied to assess personality traits in a five-factor model. The main results of the study showed that pain tolerance was significantly lower in both dominant and non-dominant hand pregnant women than in the comparison group. The studied pregnant women had higher scores for conscientiousness, fear of COVID-19, and optimism compared with the non-pregnant women. Regression analysis showed that the variability in pain perception among pregnant women could not be explained by individual differences in personality traits, optimism, and fear of COVID-19.

Endocrine Disorder in Patients With Craniopharyngioma

Craniopharyngioma is an intracranial congenital epithelial tumor growing along the pathway of the embryonic craniopharyngeal tube. The main clinical symptoms of patients with craniopharyngioma include high intracranial pressure, visual field defect, endocrine dysfunction, and hypothalamic dysfunction. At present, the preferred treatment remains the surgical treatment, but the recovery of endocrine and hypothalamic function following surgery is limited. In addition, endocrine disorders often emerge following surgery, which seriously reduces the quality of life of patients after operation. So far, research on craniopharyngioma focuses on ways to ameliorate endocrine dysfunction. This article reviews the latest research progress on pathogenesis, manifestation, significance, and treatment of endocrine disorders in patients with craniopharyngioma.

Role of Nociceptin/Orphanin FQ-NOP Receptor System in the Regulation of Stress-Related Disorders

Nociceptin/orphanin FQ (N/OFQ) is a 17-residue neuropeptide that binds the nociceptin opioid-like receptor (NOP). N/OFQ exhibits nucleotidic and aminoacidics sequence homology with the precursors of other opioid neuropeptides but it does not activate either MOP, KOP or DOP receptors. Furthermore, opioid neuropeptides do not activate the NOP receptor. Generally, activation of N/OFQ system exerts anti-opioids effects, for instance toward opioid-induced reward and analgesia. The NOP receptor is widely expressed throughout the brain, whereas N/OFQ localization is confined to brain nuclei that are involved in stress response such as amygdala, BNST and hypothalamus. Decades of studies have delineated the biological role of this system demonstrating its involvement in significant physiological processes such as pain, learning and memory, anxiety, depression, feeding, drug and alcohol dependence. This review discusses the role of this peptidergic system in the modulation of stress and stress-associated psychiatric disorders in particular drug addiction, mood, anxiety and food-related associated-disorders. Emerging preclinical evidence suggests that both NOP agonists and antagonists may represent a effective therapeutic approaches for substances use disorder. Moreover, the current literature suggests that NOP antagonists can be useful to treat depression and feeding-related diseases, such as obesity and binge eating behavior, whereas the activation of NOP receptor by agonists could be a promising tool for anxiety.

Separation from a bonded partner alters neural response to inflammatory pain in monogamous rodents

Pain experience is known to be modified by social factors, but the brain mechanisms remain unspecified. We recently established an animal model of social stress-induced hyperalgesia (SSIH) using a socially monogamous rodent, the prairie vole, in which males separated from their female partners (loss males) became anxious and displayed exacerbated inflammatory pain behaviors compared to males with partners (paired males). In the present study, to explore the neural pathways involved in SSIH, a difference in neuronal activation in pain-related brain regions, or "pain matrix", during inflammatory pain between paired and loss males was detected using Fos immunoreactivity (Fos-ir). Males were paired with a female and pair bonding was confirmed in all subjects using a partner preference test. During formalin-induced inflammatory pain, both paired and loss males showed a significant induction of Fos-ir throughout the analyzed pain matrix components compared to basal condition (without injection), and no group differences in immunoreactivity were found among the injected males in many brain regions. However, the loss males had significantly lower Fos-ir following inflammatory pain in the medial prefrontal cortex and nucleus accumbens shell than the paired males, even though base Fos-ir levels were comparable between groups. Notably, both regions with different Fos-ir are major components of the dopamine and oxytocin systems, which play critical roles in both pair bonding and pain regulation. The present results suggest the possibility that pain exacerbation by social stress emerges through alteration of signaling in social brain circuitry.

Targeting the Oxytocinergic System: A Possible Pharmacological Strategy for the Treatment of Inflammation Occurring in Different Chronic Diseases

Unresolved inflammation represents a central feature of different human pathologies including neuropsychiatric, cardiovascular, and metabolic diseases. The epidemiologic relevance of such disorders justifies the increasing interest in further understanding the mechanisms underpinning the inflammatory process occurring in such chronic diseases to provide potential novel pharmacological approaches. The most common and effective therapies for controlling inflammation are glucocorticoids; however, a variety of other molecules have been demonstrated to have an anti-inflammatory potential, including neuropeptides. In recent years, the oxytocinergic system has seen an explosion of scientific studies, demonstrating its potential to contribute to a variety of physiological processes including inflammation. Therefore, the aim of the present review was to understand the role of oxytocin in the modulation of inflammation occurring in different chronic diseases. The criterion we used to select the diseases was based on the emerging literature showing a putative involvement of the oxytocinergic system in inflammatory processes in a variety of pathologies including neurological, gastrointestinal and cardiovascular disorders, diabetes and obesity. The evidence reviewed here supports a beneficial role of oxytocin in the control of both peripheral and central inflammatory response happening in the aforementioned pathologies. Although future studies are necessary to elucidate the mechanistic details underlying such regulation, this review supports the idea that the modulation of the endogenous oxytocinergic system might represent a new potential pharmacological approach for the treatment of inflammation.

Trauma-Informed Care

Most children will experience some type of trauma during childhood, and many children suffer from significant adversities. Research in genetics, neuroscience, and epidemiology all provide evidence that these experiences have effects at the molecular, cellular, and organ level, with consequences on physical, emotional, developmental, and behavioral health across the life span. Trauma-informed care translates that science to inform and improve pediatric care and outcomes. To practically address trauma and promote resilience, pediatric clinicians need tools to assess childhood trauma and adversity experiences as well as practical guidance, resources, and interventions. In this clinical report, we summarize current, practical advice for rendering trauma-informed care across varied medical settings.

Aberrant Early in Life Stimulation of the Stress-Response System Affects Emotional Contagion and Oxytocin Regulation in Adult Male Mice

Results over the last decades have provided evidence suggesting that HPA axis dysfunction is a major risk factor predisposing to the development of psychopathological behaviour. This susceptibility can be programmed during developmental windows of marked neuroplasticity, allowing early-life adversity to convey vulnerability to mental illness later in life. Besides genetic predisposition, also environmental factors play a pivotal role in this process, through embodiment of the mother's emotions, or via nutrients and hormones transferred through the placenta and the maternal milk. The aim of the current translational study was to mimic a severe stress condition by exposing female CD-1 mouse dams to abnormal levels of corticosterone (80 µg/mL) in the drinking water either during the last week of pregnancy (PreCORT) or the first one of lactation (PostCORT), compared to an Animal Facility Rearing (AFR) control group. When tested as adults, male mice from PostCORT offspring and somewhat less the PreCORT mice exhibited a markedly increased corticosterone response to acute restraint stress, compared to perinatal AFR controls. Aberrant persistence of adolescence-typical increased interest towards novel social stimuli and somewhat deficient emotional contagion also characterised profiles in both perinatal-CORT groups. Intranasal oxytocin (0 or 20.0 µg/kg) generally managed to reduce the stress response and restore a regular behavioural phenotype. Alterations in density of glucocorticoid and mineralocorticoid receptors, oxytocin and µ- and κ-opioid receptors were found. Changes differed as a function of brain areas and the specific age window of perinatal aberrant stimulation of the HPA axis. Present results provided experimental evidence in a translational mouse model that precocious adversity represents a risk factor predisposing to the development of psychopathological behaviour.

The Neural Network of Neuropeptide S (NPS): Implications in Food Intake and Gastrointestinal Functions

The Neuropeptide S (NPS), a 20 amino acids peptide, is recognized as the endogenous ligand of a previously orphan G protein-coupled receptor, now termed NPS receptor (NPSR). The limited distribution of the NPS-expressing neurons in few regions of the brainstem is in contrast with the extensive expression of NPSR in the rodent central nervous system, suggesting the involvement of this receptor in several brain functions. In particular, NPS promotes locomotor activity, behavioral arousal, wakefulness, and unexpectedly, at the same time, it exerts anxiolytic-like properties. Intriguingly, the NPS system is implicated in the rewarding properties of drugs of abuse and in the regulation of food intake. Here, we focus on the anorexigenic effect of NPS, centrally injected in different brain areas, in both sated and fasted animals, fed with standard or palatable food, and, in addition, on its influence in the gastrointestinal tract. Further investigations, regarding the role of the NPS/NPSR system and its potential interaction with other neurotransmitters could be useful to understand the mechanisms underlying its action and to develop novel pharmacological tools for the treatment of aberrant feeding patterns and obesity.

Genetic, epigenetic, and environmental factors controlling oxytocin receptor gene expression

BACKGROUND

The neuropeptide oxytocin regulates mammalian social behavior. Disruptions in oxytocin signaling are a feature of many psychopathologies. One commonly studied biomarker for oxytocin involvement in psychiatric diseases is DNA methylation at the oxytocin receptor gene (OXTR). Such studies focus on DNA methylation in two regions of OXTR, exon 3 and a region termed MT2 which overlaps exon 1 and intron 1. However, the relative contribution of exon 3 and MT2 in regulating OXTR gene expression in the brain is currently unknown.

RESULTS

Here, we use the prairie vole as a translational animal model to investigate genetic, epigenetic, and environmental factors affecting Oxtr gene expression in a region of the brain that has been shown to drive Oxtr related behavior in the vole, the nucleus accumbens. We show that the genetic structure of Oxtr in prairie voles resembles human OXTR. We then studied the effects of early life experience on DNA methylation in two regions of a CpG island surrounding the Oxtr promoter: MT2 and exon 3. We show that early nurture in the form of parental care results in DNA hypomethylation of Oxtr in both MT2 and exon 3, but only DNA methylation in MT2 is associated with Oxtr gene expression. Network analyses indicate that CpG sites in the 3' portion of MT2 are most highly associated with Oxtr gene expression. We also identify two novel SNPs in exon 3 of Oxtr in prairie voles and a novel alternative transcript originating from the third intron of the gene. Expression of the novel alternative transcript is associated with genotype at SNP KLW2.

CONCLUSIONS

These results identify putative regulatory features of Oxtr in prairie voles which inform future studies examining OXTR in human social behaviors and disorders. These studies indicate that in prairie voles, DNA methylation in MT2, particularly in the 3' portion, is more predictive of Oxtr gene expression than DNA methylation in exon 3. Similarly, in human temporal cortex, we find that DNA methylation in the 3' portion of MT2 is associated with OXTR expression. Together, these results suggest that among the CpG sites studied, DNA methylation of MT2 may be the most reliable indicator of OXTR gene expression. We also identify novel features of prairie vole Oxtr, including SNPs and an alternative transcript, which further develop the prairie vole as a translational model for studies of OXTR.

Oxytocin modulates local topography of human functional connectome in healthy men at rest

Oxytocin has recently received remarkable attention for its role as a modulator of human behaviour. Here, we aimed to expand our knowledge of the neural circuits engaged by oxytocin by investigating the effects of intranasal and intravenous oxytocin on the functional connectome at rest in 16 healthy men. Oxytocin modulates the functional connectome within discrete neural systems, but does not affect the global capacity for information transfer. These local effects encompass key hubs of the oxytocin system (e.g. amygdala) but also regions overlooked in previous hypothesis-driven research (i.e. the visual circuits, temporal lobe and cerebellum). Increases in levels of oxytocin in systemic circulation induce broad effects on the functional connectome, yet we provide indirect evidence supporting the involvement of nose-to-brain pathways in at least some of the observed changes after intranasal oxytocin. Together, our results suggest that oxytocin effects on human behaviour entail modulation of multiple levels of brain processing distributed across different systems.

The Role of Oxytocin and the Effect of Stress During Childbirth: Neurobiological Basics and Implications for Mother and Child

The neuropeptide oxytocin acts as a hormone and a neuromodulator, influencing a multitude of human social behaviors, including reproduction. During childbirth and the postpartum period, it plays a key role in regulating and controlling processes that ensure a safe birth and the health of mother and child. Especially the onset of labor, the progress of labor and initial breastfeeding are mediated by oxytocin. In the maternal brain it controls the initiation of the mother-infant bond and the mother's emotional responses towards her child. In this review we summarize the current state of knowledge about the role of oxytocin during the different aspects and mechanisms of human childbirth, combining research from human and animal studies. Physiological and psychological stress during childbirth and lactation can have negative effects on the progress of labor, breastfeeding and bonding. We discuss how maternity caregivers can support the positive effects of oxytocin and minimize the effects of stress. Furthermore, we highlight aspects of the basic neurobiological principles and connections where further research is needed to improve our understanding of the regulation and the effects of oxytocin to support maternal and infant health.

Craniopharyngiomas primarily affecting the hypothalamus

The concept of craniopharyngiomas (CPs) primarily affecting the hypothalamus, or "hypothalamic CPs" (Hy-CPs), refers, in a restrictive sense, to the subgroup of CPs originally developing within the neural tissue of the infundibulum and tuber cinereum, the components of the third ventricle floor. This subgroup, also known as infundibulo-tuberal CPs, largely occupies the third ventricle and comprises up to 40% of this pathological entity. The small subgroup of strictly intraventricular CPs (5%), lesions wholly developed within the third ventricle above an anatomically intact third ventricle floor, can also be included within the Hy-CP category. The remaining types of sellar and/or suprasellar CPs may compress or invade the hypothalamic region during their growth but will not be considered in this review. Hy-CPs predominantly affect adults, causing a wide range of symptoms derived from hypothalamic dysfunction, such as adiposogenital dystrophy (Babinski-Fröhlich's syndrome), diabetes insipidus (DI), abnormal diurnal somnolence, and a complex set of cognitive (dementia-like, Korsakoff-like), emotional (rage, apathy, depression), and behavioral (autism-like, psychotic-like) disturbances. Accordingly, Hy-CPs represent a neurobiological model of psychiatric disorders caused by a lesion restricted to the hypothalamus. The vast majority (90%) of squamous-papillary CPs belong to the Hy-CP category. Pathologically, most Hy-CPs present extensive and strong adhesions to the surrounding hypothalamus, usually formed of a thick band of gliotic tissue encircling the central portion of the tumor ("ring-like" attachment) or its entire boundary ("circumferential" attachment). CPs with these severe adhesion types associate high surgical risk, with morbidity and mortality rates three times higher than those for sellar/suprasellar CPs. Consequently, radical surgical removal of Hy-CPs cannot be generally recommended. Rather, Hy-CPs should be accurately classified according to an individualized surgery-risk stratification scheme considering patient age, CP topography, presence of hypothalamic symptoms, tumor size, and, most importantly, the CP-hypothalamus adhesion pattern.

Plasma Oxytocin Concentrations During and After Gestation in Japanese Pregnant Women Affected by Anxiety Disorder and Endometriosis

Background

Oxytocin has a key role in mother-infant bonding, maternal care, social interaction, and stress-related psychiatric disorders. However, the factors determining oxytocin concentrations during and after pregnancy such as medical history related to nursing or parental behavior are unknown. To elucidate these, we analyzed the relationships between oxytocin concentrations during and after pregnancy, and medical history assessed in the Japan Environment and Children's Study (JECS).

Methods

We then selected the pregnant women with a medical history of anxiety disorder and endometriosis as cases and pregnant women without medical history as controls adjusting the cohort for age and parity for a nested case-control study, after which 162 women remained for analysis. We evaluated 162 pregnant women from JECS using answers provided in a questionnaire and by measuring plasma oxytocin concentration by ELISA during the first (T1) and second (T2) trimesters of pregnancy, and after childbirth (T3).

Results

Oxytocin concentration increased in a time dependent manner, consistent with previous reports. There were weak negative correlations between oxytocin concentration at T1 and the mother's age and height, but no correlation with other factors. The mean oxytocin concentrations of pregnant women with a history of an anxiety disorder (n = 7) and endometriosis (n = 13) were significantly lower than those of pregnant women with no such history at T2 and T3.

Conclusion

These results suggest that oxytocin concentrations during and after pregnancy were affected by a past history of anxiety disorder and endometriosis. This is the first study of the relationship between oxytocin concentration and endometriosis. To elucidate the molecular mechanisms, further study is needed.

Oleoylethanolamide decreases frustration stress-induced binge-like eating in female rats: a novel potential treatment for binge eating disorder

Binge eating disorder (BED) is the most frequent eating disorder, for which current pharmacotherapies show poor response rates and safety concerns, thus highlighting the need for novel treatment options. The lipid-derived messenger oleoylethanolamide (OEA) acts as a satiety signal inhibiting food intake through the involvement of central noradrenergic and oxytocinergic neurons. We investigated the anti-binge effects of OEA in a rat model of binge-like eating, in which, after cycles of intermittent food restrictions/refeeding and palatable food consumptions, female rats show a binge-like intake of palatable food, following a 15-min exposure to their sight and smell ("frustration stress"). Systemically administered OEA dose-dependently (2.5, 5, and 10 mg kg^-1) prevented binge-like eating. This behavioral effect was associated with a decreased activation (measured by mapping the expression of c-fos, an early gene widely used as a marker of cellular activation) of brain areas responding to stress (such as the nucleus accumbens and amygdala) and to a stimulation of areas involved in the control of food intake, such as the VTA and the PVN. These effects were paralleled, also, to the modulation of monoamine transmission in key brain areas involved in both homeostatic and hedonic control of eating. In particular, a decreased dopaminergic response to stress was observed by measuring dopamine extracellular concentrations in microdialysates from the nucleus accumbens shell, whereas an increased serotonergic and noradrenergic tone was detected in tissue homogenates of selected brain areas. Finally, a decrease in corticotropin-releasing factor (CRF) mRNA levels was induced by OEA in the central amygdala, while an increase in oxytocin mRNA levels was induced in the PVN. The restoration of a normal oxytocin receptor density in the striatum paralleled the oxytocinergic stimulation produced by OEA. In conclusion, we provide evidence suggesting that OEA might represent a novel potential pharmacological target for the treatment of binge-like eating behavior.

Effectiveness of breathing exercises, foot reflexology and back massage (BRM) on labour pain, anxiety, duration, satisfaction, stress hormones and newborn outcomes among primigravidae during the first stage of labour in Saudi Arabia: a study protocol for a randomised controlled trial

INTRODUCTION

Labour pain is among the severest pains primigravidae may experience during pregnancy. Failure to address labour pain and anxiety may lead to abnormal labour. Despite the many complementary non-pharmacological approaches to coping with labour pain, the quality of evidence is low and best approaches are not established. This study protocol describes a proposed investigation of the effects of a combination of breathing exercises, foot reflexology and back massage (BRM) on the labour experiences of primigravidae.

METHODS AND ANALYSIS

This randomised controlled trial will involve an intervention group receiving BRM and standard labour care, and a control group receiving only standard labour care. Primigravidae of 26-34 weeks of gestation without chronic diseases or pregnancy-related complications will be recruited from antenatal clinics. Eligible and consenting patients will be randomly allocated to the intervention or the control group stratified by intramuscular pethidine use. The BRM intervention will be delivered by a trained massage therapist. The primary outcomes of labour pain and anxiety will be measured during and after uterine contractions at baseline (cervical dilatation 6 cm) and post BRM hourly for 2 hours. The secondary outcomes include maternal stress hormone (adrenocorticotropic hormone, cortisol and oxytocin) levels, maternal vital signs (V/S), fetal heart rate, labour duration, Apgar scores and maternal satisfaction. The sample size is estimated based on the between-group difference of 0.6 in anxiety scores, 95% power and 5% α error, which yields a required sample size of 154 (77 in each group) accounting for a 20% attrition rate. The between-group and within-group outcome measures will be examined with mixed-effect regression models, time series analyses and paired t-test or equivalent non-parametric tests, respectively.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Ethical Committee for Research Involving Human Subjects of the Ministry of Health in the Saudi Arabia (H-02-K-076-0319-109) on 14 April 2019, and from the Ethics Committee for Research Involving Human Subjects (JKEUPM) Universiti Putra Malaysia on 23 October 2019, reference number: JKEUPM-2019-169. Written informed consent will be obtained from all participants. Results from this trial will be presented at regional, national and international conferences and published in indexed journals.

TRIAL REGISTRATION NUMBER

ISRCTN87414969, registered 3 May 2019.

Investigating resting brain perfusion abnormalities and disease target-engagement by intranasal oxytocin in women with bulimia nervosa and binge-eating disorder and healthy controls

Advances in the treatment of bulimia nervosa and binge-eating disorder (BN/BED) have been marred by our limited understanding of the underpinning neurobiology. Here we measured regional cerebral blood flow (rCBF) to map resting perfusion abnormalities in women with BN/BED compared with healthy controls and investigate whether intranasal oxytocin (OT), proposed as a potential treatment, can restore perfusion in disorder-related brain circuits. Twenty-four women with BN/BED and 23 healthy women participated in a randomized, double-blind, crossover, placebo-controlled study. We used arterial spin labelling MRI to measure rCBF and the effects of an acute dose of intranasal OT (40 IU) or placebo over 18-26 min post dosing, as we have previously shown robust OT-induced changes in resting rCBF in men in a similar time-window (15-36 min post dosing). We tested for effects of treatment, diagnosis and their interaction on extracted rCBF values in anatomical regions-of-interest previously implicated in BN/BED by other neuroimaging modalities, and conducted exploratory whole-brain analyses to investigate previously unidentified brain regions. We demonstrated that women with BN/BED presented increased resting rCBF in the medial prefrontal and orbitofrontal cortices, anterior cingulate gyrus, posterior insula and middle/inferior temporal gyri bilaterally. Hyperperfusion in these areas specifically correlated with eating symptoms severity in patients. Our data did not support a normalizing effect of intranasal OT on perfusion abnormalities in these patients, at least for the specific dose (40 IU) and post-dosing interval (18-26 min) examined. Our findings enhance our understanding of resting brain abnormalities in BN/BED and identify resting rCBF as a non-invasive potential biomarker for disease-related changes and treatment monitoring. They also highlight the need for a comprehensive investigation of intranasal OT pharmacodynamics in women before we can fully ascertain its therapeutic value in disorders affecting predominantly this gender, such as BN/BED.

Relationship of prenatal maternal obesity and diabetes to offspring neurodevelopmental and psychiatric disorders: a narrative review

Obesity and diabetes is a worldwide public health problem among women of reproductive age. This narrative review highlights recent epidemiological studies regarding associations of maternal obesity and diabetes with neurodevelopmental and psychiatric disorders in offspring, and provides an overview of plausible underlying mechanisms and challenges for future human studies. A comprehensive search strategy selected terms that corresponded to the domains of interest (maternal obesity, different types of diabetes, offspring cognitive functions and neuropsychiatric disorders). The databases searched for articles published between January 2010 and April 2019 were PubMed, Web of Science and CINAHL. Evidence from epidemiological studies strongly suggests that maternal pre-pregnancy obesity is associated with increased risks for autism spectrum disorder, attention-deficit hyperactivity disorder and cognitive dysfunction with modest effect sizes, and that maternal diabetes is associated with the risk of the former two disorders. The influence of maternal obesity on other psychiatric disorders is less well studied, but there are reports of associations with increased risks for offspring depression, anxiety, schizophrenia and eating disorders, at modest effect sizes. It remains unclear whether these associations are due to intrauterine mechanisms or explained by confounding family-based sociodemographic, lifestyle and genetic factors. The plausible underlying mechanisms have been explored primarily in animal models, and are yet to be further investigated in human studies.

Oxytocin in the neural control of eating: At the crossroad between homeostatic and non-homeostatic signals

The understanding of the biological substrates regulating feeding behavior is relevant to address the health problems related to food overconsumption. Several studies have expanded the conventional view of the homeostatic regulation of body weight mainly orchestrated by the hypothalamus, to include also the non-homeostatic control of appetite. Such processes include food reward and are mainly coordinated by the activation of the central mesolimbic dopaminergic pathway. The identification of endogenous systems acting as a bridge between homoeostatic and non-homeostatic pathways might represent a significant step toward the development of drugs for the treatment of aberrant eating patterns. Oxytocin is a hypothalamic hormone that is directly secreted into the brain and reaches the blood circulation through the neurohypophysis. Oxytocin regulates a variety of physiologic functions, including eating and metabolism. In the last years both preclinical and clinical studies well characterized oxytocin for its effects in reducing food intake and body weight. In the present review we summarize the role played by oxytocin in the control of both homeostatic and non-homeostatic eating, within cognitive, metabolic and reward mechanisms, to mostly highlight its potential therapeutic effects as a new pharmacological approach for the development of drugs for eating disorders. We conclude that the central oxytocinergic system is possibly one of the mechanisms that coordinate energy balance at the crossroads between homeostatic and non-homeostatic mechanisms. This concept should foster studies aimed at exploring the possible exploitation of oxytocin in the treatment of aberrant eating patterns. This article is part of the special issue on Neuropeptides.

Dysregulation of Hypothalamic Gene Expression and the Oxytocinergic System by Soybean Oil Diets in Male Mice

Soybean oil consumption has increased greatly in the past half-century and is linked to obesity and diabetes. To test the hypothesis that soybean oil diet alters hypothalamic gene expression in conjunction with metabolic phenotype, we performed RNA sequencing analysis using male mice fed isocaloric, high-fat diets based on conventional soybean oil (high in linoleic acid, LA), a genetically modified, low-LA soybean oil (Plenish), and coconut oil (high in saturated fat, containing no LA). The 2 soybean oil diets had similar but nonidentical effects on the hypothalamic transcriptome, whereas the coconut oil diet had a negligible effect compared to a low-fat control diet. Dysregulated genes were associated with inflammation, neuroendocrine, neurochemical, and insulin signaling. Oxt was the only gene with metabolic, inflammation, and neurological relevance upregulated by both soybean oil diets compared to both control diets. Oxytocin immunoreactivity in the supraoptic and paraventricular nuclei of the hypothalamus was reduced, whereas plasma oxytocin and hypothalamic Oxt were increased. These central and peripheral effects of soybean oil diets were correlated with glucose intolerance but not body weight. Alterations in hypothalamic Oxt and plasma oxytocin were not observed in the coconut oil diet enriched in stigmasterol, a phytosterol found in soybean oil. We postulate that neither stigmasterol nor LA is responsible for effects of soybean oil diets on oxytocin and that Oxt messenger RNA levels could be associated with the diabetic state. Given the ubiquitous presence of soybean oil in the American diet, its observed effects on hypothalamic gene expression could have important public health ramifications.

Influence of intranasal oxytocin on fear consolidation in healthy humans

Background

Although recent data in healthy humans suggestthat treatment with intranasal oxytocin (OT) may facilitate extinction recall,to date, little is known about the effects of OT on memory consolidationprocesses.

Aim

To examine the effect of intranasal administration of OT compared with placebo on memory consolidation blockade of a de novo fear memory in a classical 2-day fear conditioning procedure.

Results

There were no significant differences between the OT and the placebo groups on the first two extinction trials (mean (SD)=0.01 (0.39) vs 0.15 (0.31), t=−1.092, p=0.28). Similarly, during early extinction, analysis of variance for repeated measures failed to show significant main effects of extinction trials: trials (F(4, 112)=1.58, p=0.18), drug (F(1, 112)=0.13, p=0.72) or drug × trials interaction (F(4, 112)=0.76, p=0.56).

Conclusion

Our results suggest that OT administered in a double-blind fashion immediately after fear conditioning does not significantly reduce consolidation of fear learning as measured by a differential skin conductance response tested at the beginning of extinction.

Is weight status associated with peripheral levels of oxytocin? A pilot study in healthy women

The neuropeptide oxytocin is best known for its role during parturition and the milk-let down reflex. Recent evidence identifies a role for oxytocin in eating behaviour. After oxytocin administration, caloric intake is reduced with stronger inhibitory effects in individuals with obesity. Whether the experience of visual food cues affects secretion or circulating levels of oxytocin is unknown. This pilot study had three aims: 1) to measure fasting appetite hormones with a focus on plasma oxytocin concentrations; 2) determine whether healthy vs. hyperpalatable visual food cues differentially altered plasma oxytocin; and 3) assess whether appetite hormone responses to healthy vs. hyperpalatable food images depended on weight or food addiction status. Eighteen healthy women of varying weight status, with/without self-reported food addiction were recruited. Study participants completed a set of standardised questionnaires, including Yale Food Addiction Scale, and attended a one-off experimental session. Blood was collected before and after viewing two sets of food images (healthy and hyperpalatable foods). Participants were randomly allocated in a crossover design to view either healthy images or hyperpalatable foods first. A positive correlation between BMI and plasma oxytocin was found (r² = 0.32, p = 0.021) at baseline. Oxytocin levels were higher, and cholecystokinin levels lower, in food addicted (n = 6) vs. non-food addicted females (p = 0.015 and p<0.001, respectively). There were no significant changes (p>0.05) in plasma oxytocin levels in response to either healthy or hyperpalatable food images. Given that endogenous oxytocin administration tends to suppress eating behaviour; these data indicate that oxytocin receptor desensitization or oxytocin resistance may be important factors in the pathogenesis of obesity and food addiction. However, further studies in larger samples are needed to determine if peripheral oxytocin is responsive to visual food cues.

Relay of peripheral oxytocin to central oxytocin neurons via vagal afferents for regulating feeding

Oxytocin (Oxt), a neurohormone synthesized in the neurons of hypothalamic paraventricular nucleus (PVN) and supraoptic nucleus induces milk-ejection and uterine contraction and regulates social behavior, stress responses, memory and food intake. Peripheral (intraperitoneal and subcutaneous) infusion of Oxt decreases food intake and body weight in obese animals via mechanisms involving vagal afferent nerves and in obese subjects when administered nasally. Peripherally injected and intracerebroventricularly injected Oxt inhibit food intake to similar extent and with similar time course. Thus, peripheral Oxt mimics the effects of central Oxt, however, underlying mechanisms are unclear. In the present study we explored whether intraperitoneal Oxt activates Oxt neurons in PVN via vagal afferents and whether this pathway is linked to inhibition of feeding. We here show that intraperitoneal Oxt injection induces c-Fos expression in PVN largely in Oxt neurons and inhibits food intake, and these effects are blunted by subdiaphragmatic vagotomy. The intraperitoneal Oxt-induced inhibition of food intake was blunted in Oxt KO mice, by intracerebroventricular injection of Oxt receptor antagonist, and by vagotomy. These results demonstrate that intraperitoneal Oxt injection activates PVN Oxt neurons via vagal afferent nerves, thereby inhibiting food intake. This vagal afferents-mediated Oxt's peripheral-to-central coupling may serve to promote satiety and possibly a series of neural functions of Oxt and to treat their disorders.

Maternal plasma levels of oxytocin during physiological childbirth - a systematic review with implications for uterine contractions and central actions of oxytocin

Background

Oxytocin is a key hormone in childbirth, and synthetic oxytocin is widely administered to induce or speed labour. Due to lack of synthetized knowledge, we conducted a systematic review of maternal plasma levels of oxytocin during physiological childbirth, and in response to infusions of synthetic oxytocin, if reported in the included studies.

Methods

An a priori protocol was designed and a systematic search was conducted in PubMed, CINAHL, and PsycINFO in October 2015. Search hits were screened on title and abstract after duplicates were removed (n = 4039), 69 articles were examined in full-text and 20 papers met inclusion criteria. As the articles differed in design and methodology used for analysis of oxytocin levels, a narrative synthesis was created and the material was categorised according to effects.

Results

Basal levels of oxytocin increased 3–4-fold during pregnancy. Pulses of oxytocin occurred with increasing frequency, duration, and amplitude, from late pregnancy through labour, reaching a maximum of 3 pulses/10 min towards the end of labour. There was a maximal 3- to 4-fold rise in oxytocin at birth. Oxytocin pulses also occurred in the third stage of labour associated with placental expulsion. Oxytocin peaks during labour did not correlate in time with individual uterine contractions, suggesting additional mechanisms in the control of contractions. Oxytocin levels were also raised in the cerebrospinal fluid during labour, indicating that oxytocin is released into the brain, as well as into the circulation. Oxytocin released into the brain induces beneficial adaptive effects during birth and postpartum.

Oxytocin levels following infusion of synthetic oxytocin up to 10 mU/min were similar to oxytocin levels in physiological labour. Oxytocin levels doubled in response to doubling of the rate of infusion of synthetic oxytocin.

Conclusions

Plasma oxytocin levels increase gradually during pregnancy, and during the first and second stages of labour, with increasing size and frequency of pulses of oxytocin. A large pulse of oxytocin occurs with birth. Oxytocin in the circulation stimulates uterine contractions and oxytocin released within the brain influences maternal physiology and behaviour during birth. Oxytocin given as an infusion does not cross into the mother’s brain because of the blood brain barrier and does not influence brain function in the same way as oxytocin during normal labour does.

Electronic supplementary material

The online version of this article (10.1186/s12884-019-2365-9) contains supplementary material, which is available to authorized users.

Putting Your Trauma Lens On

Trauma in childhood is now understood to cause long-term effects on the brain and body. The pediatric provider, using a "trauma lens," which constitutes observing a child's attachment, resilience, and stress response, is well poised to identify and support children and families at risk. Fortunately, resilience is a dynamic process that can be learned, enhanced, and supported. Familiarity with the most common symptoms of traumatic stress will help the medical provider quickly recognize which children are impacted or FRAYED (Fits, Frets, and Fear; Regulation disorders; Attachment problems; Yawning and Yelling; Educational and developmental delays; Defeat and Dissociation). Once symptoms are identified, the caregiver can "focus" on attachment and resilience skills, the THREADS (Thinking & learning brain, with opportunity for continued growth; cognitive development; Hope, optimism, faith, belief in a future for one's self; Regulation [self-regulation, self-control]; Efficacy, or knowing one can impact their environment and situation; Attachment, secure; Development, or mastery of age-salient developmental tasks; Social context or the larger network of relationships in which one lives and learns) that can be woven together to promote resilience. Guiding families with empathy and positive regard, the medical provider can help the child and family rebuild resilience skills. Organizing practical guidance around the "3 R's"-Reassuring, Restoring routines, and Regulating-is a roadmap to recovery. [Pediatr Ann. 2019;48(7):e269-e273.].

Oxytocin alterations and neurocognitive domains in patients with hypopituitarism

PURPOSE

Oxytocin is a hypothalamus derived, posterior pituitary stored nonapeptide which has gained recent interest as an important neuropsychiatric and metabolic hormone beyond its classic role in lactation and parturition. Hypopituitarism is a heterogenous disorder of derangement in one or more anterior or posterior pituitary hormones. Diagnosis of deficiency and hormone replacement exists to address all relevant axes except for oxytocin. Our study aims to define derangements in oxytocin in a unique population of patients with hypopituitarism and correlate levels with measures of emotional health and quality of life.

METHODS

A cross-sectional, single day study was completed to measure plasma oxytocin levels in a diverse population of patients with hypopituitarism compared to controls. Subjects also completed depression, quality of life and stress-related questionnaires, and emotion recognition tasks.

RESULTS

Thirty-eight subjects completed the study, 18 with hypopituitarism (9 with diabetes insipidus) and 20 controls. After controlling for differences in age, weight and gender, plasma oxytocin levels were highest in subjects with diabetes insipidus compared to control [mean, IQR: 44.3 pg/ml (29.8-78.2) vs. 20.6 (17-31.3), p = 0.032]. Amongst hypopituitary subjects, those with duration of disease greater than 1 year had higher oxytocin levels. No significant differences were observed for psychosocial measures including emotion recognition tasks.

CONCLUSIONS

Plasma oxytocin levels were found higher in patients with hypopituitarism compared to controls and highest in those with diabetes insipidus. Longer duration of hypopituitarism was also associated with higher plasma levels of oxytocin. Further study is needed to better define oxytocin deficiency and investigate response to treatment.

Oxytocin attenuates phencyclidine hyperactivity and increases social interaction and nucleus accumben dopamine release in rats

The pituitary neuropeptide oxytocin promotes social behavior, and is a potential adjunct therapy for social deficits in schizophrenia and autism. Oxytocin may mediate pro-social effects by modulating monoamine release in limbic and cortical areas, which was investigated herein using in vivo microdialysis, after establishing a dose that did not produce accompanying sedative or thermoregulatory effects that could concomitantly influence behavior. The effects of oxytocin (0.03-0.3 mg/kg subcutaneous) on locomotor activity, core body temperature, and social behavior (social interaction and ultrasonic vocalizations) were examined in adult male Lister-hooded rats, using selective antagonists to determine the role of oxytocin and vasopressin V_1a receptors. Dopamine and serotonin efflux in the prefrontal cortex and nucleus accumbens of conscious rats were assessed using microdialysis. 0.3 mg/kg oxytocin modestly reduced activity and caused hypothermia but only the latter was attenuated by the V_1a receptor antagonist, SR49059 (1 mg/kg intraperitoneal). Oxytocin at 0.1 mg/kg, which did not alter activity and had little effect on temperature, significantly attenuated phencyclidine-induced hyperactivity and increased social interaction between unfamiliar rats without altering the number or pattern of ultrasonic vocalizations. In the same rats, oxytocin (0.1 mg/kg) selectively elevated dopamine overflow in the nucleus accumbens, but not prefrontal cortex, without influencing serotonin efflux. Systemic oxytocin administration attenuated phencyclidine-induced hyperactivity and increased pro-social behavior without decreasing core body temperature and selectively enhanced nucleus accumbens dopamine release, consistent with activation of mesocorticolimbic circuits regulating associative/reward behavior being involved. This highlights the therapeutic potential of oxytocin to treat social behavioral deficits seen in psychiatric disorders such as schizophrenia.

The relationship between oxytocin, dietary intake and feeding: A systematic review and meta-analysis of studies in mice and rats

The neuropeptide oxytocin has been associated with food intake and feeding behaviour. This systematic review aimed to investigate the impact of oxytocin on dietary intake and feeding behaviour in rodent studies. Six electronic databases were searched to identify published studies to April 2018. Preclinical studies in mice and rats were included if they reported: (1) a dietary measure (i.e. food or nutrient and/or behaviour (2) an oxytocin measure, and (3) relationship between the two measures. A total of 75 articles (n = 246 experiments) were included, and study quality appraised. The majority of studies were carried out in males (87%). The top three oxytocin outcomes assessed were: exogenous oxytocin administration (n = 126), oxytocin-receptor antagonist administration (n = 46) and oxytocin gene deletion (n = 29). Meta-analysis of exogenous studies in mice (3 studies, n = 43 comparisons) and rats (n = 8 studies, n = 82 comparisons) showed an overall decrease in food intake with maximum effect shown at 2 h post-administration.

Sex Differences in Salivary Oxytocin and Cortisol Concentration Changes during Cooking in a Small Group

Background: Oxytocin (OT), a neuropeptide, has positive effects on social and emotional processes during group activities. Because cooking is an integrated process in the cognitive, physical, and socio-emotional areas, cooking in a group is reported to improve emotion and cognition. However, evidence for efficacy in group cooking has not been well established at the biological level. Methods: To address this shortcoming, we first measured salivary levels of OT and cortisol (CORT), a biomarker of psychological stress, before and after group cooking for approximately 1 h by people who know each other in healthy married or unmarried men and women. We then compared the initial OT and CORT concentrations with those during individual non-cooking activities in isolation. Results: Baseline OT concentrations before group and non-group sessions did not significantly differ and OT levels increased after both types of activity in men and women. In men, however, the percentage changes of OT levels in the first over the second saliva samples were significantly small during cooking compared with those in individual activities. In women, however, such a difference was not observed. In contrast, the mean salivary CORT concentrations after group cooking were significantly decreased from the baseline level in both sexes, though such decreases were not significant after individual activity sessions. The sex-specific differences were marital-status independent. Conclusion: These results indicate that OT and CORT concentrations after two activity sessions by a familiar group changed in opposite directions in a sex-specific manner. This suggests that, because cooking is experience-based, we need to consider the sex-specific features of group cooking if we apply it for intervention.

Histamine-deficient mice do not respond to the antidepressant-like effects of oleoylethanolamide

It has been suggested that the bioactive lipid mediator oleoylethanolamide (OEA), a potent agonist of the peroxisome proliferator-activated receptor-alpha (PPAR-α) possesses anti-depressant-like effects in several preclinical models. We recently demonstrated that several of OEA's behavioural actions require the integrity of the brain histaminergic system, and that an intact histaminergic neurotransmission is specifically required for selective serotonin re-uptake inhibitors to exert their anti-depressant-like effect. The purpose of our study was to test if OEA requires the integrity of the histaminergic neurotransmission to exert its antidepressant-like effects. Immobility time in the tail suspension test was measured to assess OEA's potential (10 mg/kg i.p.) as an antidepressant drug in histidine decarboxylase null (HDC^-/-) mice and HDC^+/+ littermates, as well as in PPAR-α^+/+ and PPAR-α^-/- mice. CREB phosphorylation was evaluated using Western blot analysis in hippocampal and cortical homogenates, as pCREB is considered partially responsible for the efficacy of antidepressants. Serotonin release from ventral hippocampi of HDC^+/+ and HDC^-/- mice was measured with in-vivo microdialysis, following OEA administration. OEA decreased immobility time and increased brain pCREB levels in HDC^+/+ mice, whereas it was ineffective in HDC^-/- mice. Comparable results were obtained in PPAR-α^+/+ and PPAR-α^-/- mice. Microdialysis revealed a dysregulation of serotonin release induced by OEA in HDC^-/- mice. Our observations corroborate our hypothesis that brain histamine and signals transmitted by OEA interact to elaborate appropriate behaviours and may be the basis for the efficacy of OEA as an antidepressant-like compound.

Chronic Hypopituitarism Associated with Increased Postconcussive Symptoms Is Prevalent after Blast-Induced Mild Traumatic Brain Injury

The most frequent injury sustained by US service members deployed to Iraq or Afghanistan is mild traumatic brain injuries (mTBI), or concussion, by far most often caused by blast waves from improvised explosive devices or other explosive ordnance. TBI from all causes gives rise to chronic neuroendocrine disorders with an estimated prevalence of 25-50%. The current study expands upon our earlier finding that chronic pituitary gland dysfunction occurs with a similarly high frequency after blast-related concussions. We measured circulating hormone levels and accessed demographic and testing data from two groups of male veterans with hazardous duty experience in Iraq or Afghanistan. Veterans in the mTBI group had experienced one or more blast-related concussion. Members of the deployment control (DC) group encountered similar deployment conditions but had no history of blast-related mTBI. 12 of 39 (31%) of the mTBI participants and 3 of 20 (15%) veterans in the DC group screened positive for one or more neuroendocrine disorders. Positive screens for growth hormone deficiency occurred most often. Analysis of responses on self-report questionnaires revealed main effects of both mTBI and hypopituitarism on postconcussive and posttraumatic stress disorder (PTSD) symptoms. Symptoms associated with pituitary dysfunction overlap considerably with those of PTSD. They include cognitive deficiencies, mood and anxiety disorders, sleep problems, diminished quality of life, deleterious changes in metabolism and body composition, and increased cardiovascular mortality. When such symptoms are due to hypopituitarism, they may be alleviated by hormone replacement. These findings suggest consideration of routine post-deployment neuroendocrine screening of service members and veterans who have experienced blast-related mTBI and are reporting postconcussive symptoms.

The morphometric co-atrophy networking of schizophrenia, autistic and obsessive spectrum disorders

By means of a novel methodology that can statistically derive patterns of co-alterations distribution from voxel-based morphological data, this study analyzes the patterns of brain alterations of three important psychiatric spectra-that is, schizophrenia spectrum disorder (SCZD), autistic spectrum disorder (ASD), and obsessive-compulsive spectrum disorder (OCSD). Our analysis provides five important results. First, in SCZD, ASD, and OCSD brain alterations do not distribute randomly but, rather, follow network-like patterns of co-alteration. Second, the clusters of co-altered areas form a net of alterations that can be defined as morphometric co-alteration network or co-atrophy network (in the case of gray matter decreases). Third, within this network certain cerebral areas can be identified as pathoconnectivity hubs, the alteration of which is supposed to enhance the development of neuronal abnormalities. Fourth, within the morphometric co-atrophy network of SCZD, ASD, and OCSD, a subnetwork composed of eleven highly connected nodes can be distinguished. This subnetwork encompasses the anterior insulae, inferior frontal areas, left superior temporal areas, left parahippocampal regions, left thalamus and right precentral gyri. Fifth, the co-altered areas also exhibit a normal structural covariance pattern which overlaps, for some of these areas (like the insulae), the co-alteration pattern. These findings reveal that, similarly to neurodegenerative diseases, psychiatric disorders are characterized by anatomical alterations that distribute according to connectivity constraints so as to form identifiable morphometric co-atrophy patterns.

Oxytocin is lower in African American men with diabetes and associates with psycho-social and metabolic health factors

Objective

Recently, it has been suggested that oxytocin (OT) has a role in metabolism and neuropsychiatry health and disease, and therefore, it may represent a potential therapeutic target. The current study aimed to investigate relationships between OT and glycemic status along with psycho-social and behavioral factors.

Design and methods

A total of 92 obese or overweight, African American, male subjects were enrolled in the study. Biometric and biochemical data were collected including oral glucose tolerance testing and urinary OT (measured by ELISA). Subjects also completed questionnaires on social and lifestyle factors.

Results

OT levels were found to be significantly lower in subjects with type 2 diabetes mellitus (T2DM) compared to normal glucose tolerance (p<0.05). When stratified by OT tertiles, subjects with higher OT had lower weight, body mass index (BMI) and hemoglobin A1c, but higher eGFR which remained significant after BMI adjustment. The highest OT tertile also had more smokers and more users of psychiatric medications. A stepwise ordered logistic regression supported these findings and could account for 21% of the variation in OT categories (pseudoR² = 0.21).

Conclusions

In this unique population, OT was found lower in subjects with diabetes but higher with better renal function, cigarette smoking and use of psychiatric medications. Future studies are needed to confirm these findings and examine the potential therapeutic role of OT.

Oxytocin and Eating Disorders: A Narrative Review on Emerging Findings and Perspectives

BACKGROUND

The hypothalamic neuropeptide oxytocin regulates reproductive behavior and mother-infant interaction, and conclusive studies in humans indicate that oxytocin is also a potent modulator of psychosocial function. Pilot experiments have yielded first evidence that this neuropeptide moreover influences eating behavior.

METHODS

We briefly summarize currently available studies on the involvement of the oxytocin system in the pathophysiology of eating disorders, as well as on the effects of oxytocin administration in patients with these disorders.

RESULTS

Brain administration of oxytocin in animals with normal weight, but also with diet-induced or genetically induced obesity, attenuates food intake and reduces body weight. In normal-weight and obese individuals, acute intranasal oxytocin delivery curbs calorie intake from main dishes and snacks. Such effects might converge with the poignant social and cognitive impact of oxytocin to also improve dysfunctional eating behavior in the therapeutic context. This assumption has received support in first studies showing that oxytocin might play a role in the disease process of anorexia nervosa. In contrast, respective experiments in patients with bulimia nervosa and binge eating disorder are still scarce.

CONCLUSIONS

We propose a framework of oxytocin's role and its therapeutic potential in eating disorders that aims at integrating social and metabolic aspects of its pharmacological profile, and ponder perspectives and limitations of oxytocin use in the clinical setting.

Salivary Oxytocin Concentration Changes during a Group Drumming Intervention for Maltreated School Children

Many emotionally-disturbed children who have been maltreated and are legally separated from their parents or primary caregivers live in group homes and receive compulsory education. Such institutions provide various special intervention programs. Taiko-ensou, a Japanese style of group drumming, is one such program because playing drums in a group may improve children’s emotional well-being. However, evidence for its efficacy has not been well established at the biological level. In this study, we measured salivary levels of oxytocin (OT), a neuropeptide associated with social memory and communication, in three conditions (recital, practice, and free sessions) in four classes of school-aged children. Following the sessions, OT concentrations showed changes in various degrees and directions (no change, increases, or decreases). The mean OT concentration changes after each session increased, ranging from 112% to 165%. Plasma OT concentrations were equally sensitive to drum playing in school-aged boys and girls. However, the difference between practice and free play sessions was only significant among elementary school boys aged 8–12 years. The results suggest that younger boys are most responsive to this type of educational music intervention.

Polymorphisms of the oxytocin receptor gene and overeating: the intermediary role of endophenotypic risk factors

Background/Objectives:

Oxytocin (OXT) is an evolutionarily ancient neuropeptide with strong links to affiliative and prosocial behaviors, and the management of stress. Increases in OXT also tend to decrease food intake, especially of sweet carbohydrates. The social correlates of low OXT levels mesh with the social deficits and stress proneness identified in interpersonal models of overeating, as well as the increased appetite for highly palatable foods typically seen in chronic overeaters. The objectives of this study were to investigate links between polymorphisms of the oxytocin receptor (OXTR) gene and overeating, and to examine OXTR links with relevant endophenotypes of overeating related to reward and stress sensitivity, and to food preferences.

Subject/Methods:

The sample comprised 460 adults between the ages of 25 and 50 years recruited from the community, and representing a broad range of body weights. Overeating, reward and punishment sensitivity, and food preferences, were quantified as composite variables using well-validated questionnaires. In addition, seven single-nucleotide polymorphisms (rs237878, rs237885, rs2268493, rs2268494, rs2254298, rs53576, rs2268498) of the OXTR gene were genotyped.

Results:

Analyses identified a four-marker haplotype that was significantly related to food preferences. Individual genotype analyses also found that at least one of the markers was related to each of the phenotypic variables. In addition, an empirically derived structural equation model linking genetic and phenotype variables produced a good fit to the data.

Conclusions:

The results of this preliminary study have demonstrated that OXTR variation is associated with overeating, and with endophenotypic traits such as sweet and fatty food preferences, and reward and punishment sensitivity. In general, the genetic findings also favor the view that overeating may be associated with relatively low basal OXT levels.

First experiences with neuropsychological effects of oxytocin administration in childhood-onset craniopharyngioma

PURPOSE

The hypothalamic hormone oxytocin plays a major role in regulation of behavior and body composition. Quality of survival is frequently impaired in childhood craniopharyngioma patients due to sequelae such as behavioral deficits and severe obesity caused by tumor or treatment-related hypothalamic lesions.

METHODS

In our pilot cross-sectional study, we analyzed emotion recognition abilities and oxytocin concentrations in saliva and urine before and after single nasal administration of 24 IU oxytocin in 10 craniopharyngioma patients. Four craniopharyngioma presented with grade I lesions (limited to anterior hypothalamic areas) and 6 craniopharyngioma with grade II lesions (involving mammillary bodies and posterior hypothalamic areas). Emotional tasks were assessed before and after administration of oxytocin using the Geneva multimodal emotion portrayals corpus and the Multidimensional Mood Questionnaire.

RESULTS

All patients presented with detectable levels of oxytocin before administration. Nasal administration of oxytocin was well-tolerated and resulted in increased oxytocin concentrations in saliva and urine. After oxytocin administration, craniopharyngioma patients with postsurgical lesions limited to the anterior hypothalamus area showed improvements in emotional identifications compared to craniopharyngioma patients with lesions of anterior and posterior hypothalamic areas. Focusing on correct assignments to positive and negative emotion categories, craniopharyngioma patients improved assignment to negative emotions.

CONCLUSIONS

Oxytocin might have positive effects on emotion perception in craniopharyngioma patients with specific lesions of the anterior hypothalamic area. Further studies on larger cohorts are warranted.

Microglial Intracellular Ca2+ Signaling in Synaptic Development and its Alterations in Neurodevelopmental Disorders

Autism spectrum disorders (ASDs) are neurodevelopmental disorders characterized by deficits in social interaction, difficulties with language and repetitive/restricted behaviors. Microglia are resident innate immune cells which release many factors including proinflammatory cytokines, nitric oxide (NO) and brain-derived neurotrophic factor (BDNF) when they are activated in response to immunological stimuli. Recent in vivo imaging has shown that microglia sculpt and refine the synaptic circuitry by removing excess and unwanted synapses and be involved in the development of neural circuits or synaptic plasticity thereby maintaining the brain homeostasis. BDNF, one of the neurotrophins, has various important roles in cell survival, neurite outgrowth, neuronal differentiation, synaptic plasticity and the maintenance of neural circuits in the CNS. Intracellular Ca²⁺ signaling is important for microglial functions including ramification, de-ramification, migration, phagocytosis and release of cytokines, NO and BDNF. BDNF induces a sustained intracellular Ca²⁺ elevation through the upregulation of the surface expression of canonical transient receptor potential 3 (TRPC3) channels in rodent microglia. BDNF might have an anti-inflammatory effect through the inhibition of microglial activation and TRPC3 could play important roles in not only inflammatory processes but also formation of synapse through the modulation of microglial phagocytic activity in the brain. This review article summarizes recent findings on emerging dual, inflammatory and non-inflammatory, roles of microglia in the brain and reinforces the importance of intracellular Ca²⁺ signaling for microglial functions in both normal neurodevelopment and their potential contributing to neurodevelopmental disorders such as ASDs.

Increased intake of energy-dense diet and negative energy balance in a mouse model of chronic psychosocial defeat

PURPOSE

Chronic exposure to stress may represent a risk factor for developing metabolic and eating disorders, mostly driven by the overconsumption of easily accessible energy-dense palatable food, although the mechanisms involved remain still unclear. In this study, we used an ethologically oriented murine model of chronic stress caused by chronic psychosocial defeat (CPD) to investigate the effects of unrestricted access to a palatable high fat diet (HFD) on food intake, body weight, energy homeostasis, and expression of different brain neuropeptides. Our aim was to shed light on the mechanisms responsible for body weight and body composition changes due to chronic social stress.

METHODS

In our model of subordinate (defeated), mice (CPD) cohabitated in constant sensory contact with dominants, being forced to interact on daily basis, and were offered ad libitum access either to an HFD or to a control diet (CD). Control mice (of the same strain as CPD mice) were housed in pairs and left unstressed in their home cage (UN). In all these mice, we evaluated body weight, different adipose depots, energy metabolism, caloric intake, and neuropeptide expression.

RESULTS

CPD mice increased the intake of HFD and reduced body weight in the presence of enhanced lipid oxidation. Resting energy expenditure and interscapular brown adipose tissue (iBAT) were increased in CPD mice, whereas epididymal adipose tissue increased only in HFD-fed unstressed mice. Propiomelanocortin mRNA levels in hypothalamic arcuate nucleus increased only in HFD-fed unstressed mice. Oxytocin mRNA levels in the paraventricular nucleus and neuropeptide Y mRNA levels within the arcuate were increased only in CD-fed CPD mice. In the arcuate, CART was increased in HFD-fed UN mice and in CD-fed CPD mice, while HFD intake suppressed CART increase in defeated animals. In the basolateral amygdala, CART expression was increased only in CPD animals on HFD.

CONCLUSIONS

CPD appears to uncouple the intake of HFD from energy homeostasis causing higher HFD intake, larger iBAT accumulation, increased energy expenditure and lipid oxidation, and lower body weight. Overall, the present study confirms the notion that the chronic activation of the stress response can be associated with metabolic disorders, altered energy homeostasis, and changes of orexigenic and anorexigenic signaling. These changes might be relevant to better understand the etiology of stress-induced obesity and eating disorders and might represent a valid therapeutic approach for the development of new therapies in this field.